1. Field of the Invention
The present invention relates to a direction indicating device, and more particularly, to a direction indicating device capable of enhancing accuracy, durability and reliability.
2. Description of the Prior Art
A direction indicating device is an electronic device for generating direction instructions, and can be applied to a computer system, a multimedia device, an entertainment equipment, a household appliance, a tool machine etc. Normally, a direction indicating device comprises keys or trigger units corresponding to four directions (up, down, left and right), such as direction keys in a keyboard, a joystick of a game console.
A direction indicating device realized by keys can be easily assembled, but does not accurately respond to user's demand. Please refer to FIG. 1A, which is a schematic diagram of a conventional key-based direction indicating device 10. The direction indicating device 10 mainly includes keys PAD_UP, PAD_DW, PAD_LT, PAD_RT, corresponding to four directions up, down, left and right, respectively. Bottoms of the keys PAD_UP, PAD_DW, PAD_LT, PAD_RT are coated with a conductive material, such as graphite, and are formed with elastic mechanisms, for evenly keeping a fixing distance between the conductive material and detection circuits DET_UP, DET_DW, DET_LT, DET_RT. The detection circuits DET_UP, DET_DW, DET_LT, DET_RT are connected to a controller (not shown in FIG. 1A). The controller generates a corresponding direction control instruction according to whether the detection circuit is turned on. For example, when a user presses the key PAD_UP, the conductive material underneath the key PAD_UP touches the detection circuit DET_UP, such that the detection circuit DET_UP is turned on. Accordingly, the controller determines a user presses the key PAD_UP, and outputs the corresponding direction instruction.
As can be seen from the above, when one of the detection circuits DET_UP, DET_DW, DET_LT, DET_RT is turned on, the controller generates the corresponding direction instruction. However, such one-or-zero method does not respond demand in between, such as Graphical User Interface (GUI) applications.
In addition, no matter a computer game or a TV game console is operated by the usage of a keyboard or a joystick, a game software or a joystick controller determines direction, velocity, and acceleration of movement according to trigger times and trigger period of keys corresponding to specific directions. For example, please refer to FIG. 1B, which is a schematic diagram of a direction control module 12 of a conventional joystick. In the direction control module 12, a region surrounded by a dotted line represents a position of a control stick. Similar to the operations of the key-based direction indicating device 10, when the user forces the control stick to touch one of trigger units TR_UP, TR_DW, TR_LT, TR_RT, the touched trigger unit sends a signal to a joystick controller, so as to generate a corresponding direction instruction. For example, when the user forces the control stick upwardly to touch the trigger unit TR_UP, the trigger unit TR_UP sends a corresponding “up” direction instruction. Then the game software determines direction, velocity, and acceleration of movement according to times, periods of the direction instruction, and makes the corresponding response.
Both of the key-based direction indicating device 10 and the direction control module 12 for a joystick utilize the keys or the trigger units corresponding to different directions, which act as switches. Such kind of operation is favorable for a menu-based operation, but does not accurately respond to user control for GUI or game operations.